“For every action, there is an equal and opposite reaction” is Newton’s third law of physics. Its counterpart in geopolitics is “blowback,” when military action in one sphere produces an unintended and undesirable consequence in another. September 11, 2001, was blowback. George H.W. Bush had sent an army of half a million to hurl Saddam Hussein out of Kuwait, a triumph. He proceeded to impose severe sanctions on the Iraqis and to build U.S. bases in Saudi Arabia. “Infidel” soldiers on sacred Islamic soil and the suffering of the Iraqi people under American sanctions were two of the causes Osama bin Laden listed in his declaration of war on the United States. Our 3,000 dead on 9/11 were blowback for having established a neo-imperial presence in the Arabian Peninsula after Desert Storm.